Orally administered medicaments are given to the patient in many forms, such as liquid solutions, emulsions, or suspensions, or in solid form such as capsules or tablets (as used herein, the term "tablet" means any shaped and compressed solid dosage form, including caplets). Medicaments administered in tablet or capsule form are usually intended to be swallowed whole. Therefore, the often disagreeable taste of the active ingredient need not be taken into account in formulating the dosage form, except for the provision of means to prevent the taste from being apparent during the short time that the dosage form is in the mouth. Such means may include the use of an appropriately thin and quickly dissolving coating on the tablet, the use of the gelatin capsule form, or simply compressing a tablet firmly so that it will not begin to disintegrate during the short time that it is intended to be in the mouth.
It is desirable to provide the medicine either in liquid form or in a chewable solid form for children, especially toddlers, older persons, and many other persons, that have trouble swallowing whole tablets and capsules. Even where the medicine can be formulated as a liquid, it is desirable also to be able to provide a chewable solid form for convenience.
A common problem with chewable tablet forms is the often disagreeable taste of the active ingredient which manifests itself during chewing. In some cases, the taste of the active medicament in a tablet can be masked by adding flavoring ingredients to the tablet.
A different approach was taken with a children's size tablet containing acetaminophen (acetyl para-amino phenol or "APAP"). A children's size tablet of APAP is available commercially wherein the APAP is present in granules that are coated with ethyl cellulose. A significant proportion of the APAP remains shielded by the coating (and therefore does not contribute to taste) while the tablet is in the mouth, despite some breakage of the ethyl cellulose coating during compression of the tablet and some additional breakage of the coating during chewing. The APAP becomes available via permeation through the coating (although ethyl cellulose is not soluble in aqueous fluids, water does permeate through the coating) and from the granules wherein the coating was broken.
U.S. Pat. No. 5,075,114 issued to Edward J. Roche on Dec. 24, 1991 (incorporated herein by reference), describes chewable tablets prepared by coating compressed granulated active acetaminophen, using fluidized bed coating. Combinations of two or more of pseudoephedrine HCl, chlorpheniramine maleate, dextromethorphan HBr, diphenhydramine HCl or citrate, acetaminophen, ibuprofen, and naproxen are contemplated, but it is also suggested that coatings may be varied to provide a slower release of one medicament over another, indicating discrete granules of each medicament. The coatings comprised about 5 to about 28% of the total dry weight of the granule and comprised a polymer blend.
U.S. Pat. No. 5,260,072 issued to Edward J. Roche, et al. on Nov. 9, 1993 (incorporated herein by reference) describes rotor granulations and tastemasking coatings comprising polymer blends of one or both of cellulose acetate or cellulose acetate butyrate and polyvinylpyrrolidone. The inclusion of two or more medicaments is contemplated, but it is also indicated that the coatings for each medicament can be varied, suggesting discrete granules of each medicament.
Commonly assigned copending application Ser. No. 08/166 111, filed Dec. 13, 1993, now U.S. Pat. No. 5,489,436 to Michael R. Hoy, et al. (incorporated herein by reference) describes chewable tablets comprising rotor granules coated with polymer blends including cellulose acetate and methyl aminoethyl methacrylate neutral methacrylic acid ester (the preferred representative compound being Eudragit.RTM. E-100). The coating method described is fluid bed coating. The inclusion of two or more medicaments is contemplated, but not described by example.
A need remains for a chewable tablet comprising more than one active ingredient without sacrificing taste. This is particularly important for children.